The 81-year-old's Fashion Police co-host Kelly Osbourne said she was inconsolable, tweeting: "4 the first time in years I got down on my knees & prayed tonight! I encourage U 2 do the same 4 @Joan_Rivers my grandma! #inconsolable."

While Hollywood hellraiser Charlie Sheen wrote: "@joan_rivers Please come back to us young lady. Your inimitable genius and compassion keeps a world you set in motion, a lot better every day. Love and peace."

Another one of her co-hosts Giuliana Rancic also said she was praying for Joan and her distraught daughter Mel.

"Praying for @Joan_Rivers and @MelRivers. Even though Joan's the strongest woman I know, every single prayer counts. I love you, Joan."

Courtney Love shared: "Hang in there @Joan_Rivers So many awful gowns are going to be worn this year as bait for you to pull through. Love and prayers Court."

Earlier this week the American comedienne was rushed to hospital in New York after she stopped breathing while having surgery on her vocal chords.

The acid-tongued comic, who was initially placed in a medically-induced coma, is now completely reliant on the machine to keep her alive.

According to reports in the US, her family, led by daughter Melissa, are hopeful she will take a turn for the better.

However sources say the family will have to consider turning off her life support if the situation does not improve.

Insiders say the 81-year-old would not want to live unless she could enjoy “a full and active life ... (she) would never want to be a burden on anyone.” on Thursday after she stopped breathing during surgery on her throat.

She had been undergoing treatment on her vocal chords when medics noticed she was suffering complications.

(Photo: Rex Features)

A 911 call was made at 9:39am on Thursday with the caller telling the operator: “We have somebody in either cardiac or respiratory arrest.”

Rivers, who is well known for her use of plastic surgery, was rushed to Mount Sinai Hospital in Manhattan where her daughter Melissa rushed to be at her bedside from LA.

She had showed no sign she was about to undergo surgery on Tuesday as she tapped a special 90 minute edition of the American show Fashion Police which aired that night

The mum-of-one had begun her hectic weekly schedule on Sunday working for the programme attending the Video Music Awards and then the Emmys the following night.

Just hours before the operation she was tweeting her 2.1million followers telling them to watch highlights of TV award ceremony.